Bottom "toolbar" is not there; cannot make new material because of it,
You need to go in the shader editor to create a new material, not in the the texture node editor.


However, if you want to edit a texture, you need first to add one in the texture properties. This will enable the check-button "Use nodes" in the texture node editor.
These textures are not a material, but can be used when sculpting or painting your material. They can also be used by certain modifiers.



You need to set the texture type to "brush" and check "use nodes" :